Question

(i) What is Forensic chemistry related to?
(ii) What is the need for chemical fertilizers in crop fields?
(iii) Explain any two types of dyes based on their method of application.

Answer 1

(i) Forensic chemistry applies scientific principles, techniques, and methods to the investigation of crime.

(ii) Fertilizers replace the nutrients that crops remove from the soil. Without the addition of fertilizers, crop yields and agricultural productivity would be significantly reduced. That's why mineral fertilizers are used to supplement the soil's nutrient stocks with minerals that can be quickly absorbed and used by crops.

(iii)1. Direct Dyes:

• They have a high affinity for cotton, rayon and other cellulose fibre.

• So they are applied directly as they fix firmly on the fabric.
  Example: Congo red.

2. Vat Dyes:

• It can be used only on cotton and, not on silk and wool.

• This dyeing is a continuous process and is carried out in a large vessel called a vat.

• So it is called a Vat dye.
  Example: Indigo